Most knowledge about the deeper interior of the earth is derived from seismological records. Seismic waves generated by earthquakes travel through the globe and sample its major structures on the way. Important information about seismic velocities and densities, structural boundaries, mineral composition, temperature and pressure regimes etc are hidden in each recorded seismogram and can be retrieved by inverse methods. To obtain a complete picture, globally distributed high quality broadband seismological stations are required to record a full seismologically range in terms of frequency content (10**2 – 10**-6 Hz) and dynamic range (10**-9 – 10**-1 m/s). The technical equipment of the GEOFON network fullfills these requirements and is installed in 50 stations worldwide. (Near) real-time data transmission (via the Internet) from most stations makes the GEOFON data immediately available to the scientifc community and provides a perfect tool for rapid determination of earthquake source parameters for scientific purposes but also for earthquake and tsunami early warnings and for use by disaster management. Both near real-time and archive data are openly available to the community from the GEOFON Data Center and are shared with other national and international data centers such as the european ORFEUS Data Center in De Bilt (Netherlands) and the global FDSN/IRIS Data Center (Seattle, USA).

Logistics Summary

This project makes broadband seismological recordings of global earthquakes at Summit, Greenland. Formerly a part of the temporary GLATIS network, project responsibility has been turned over to GFZ Potsdam. Summit instruments have been included in that institute's GEOFON network. The PI (Hanka, then Strollo starting in 2015) will visit Summit Station annually to service and maintain the project's seismological station. Over the years, in addition to the scheduled maintenance, project personnel have visited Summit for various other project needs: In 2002, they installed an upgraded datalogger for the seismological station and a "Seiscomp" box that connected the station to the Summit LAN for Internet real-time data transmission; in 2004, another major station upgrade overcame technical problems and minimized required local support; finally, in 2007, two technicians raised and relocated the seismometer bunker, routing power and communications connections out of the Temporary Atmospheric Watch Observatory. In 2009, a technician will return to Summit in May to conduct minor maintenance on the seismometer. Station staff will assist the technician as needed with excavation of the bunker and maintenance activities. Year-round, science technical staff will re-level the instrument and provide as-needed assistance. In 2010, a team of two researchers will return to Summit in July. The seismometer bunker will be raised and relocated to a new site so that power and communications can continue to be connected out of the Temporary Atmospheric Watch Observatory, which is also being relocated during this time. Station staff will assist the technicians as needed with excavation of the bunker and maintenance activities. Year-round, science technical staff will re-level the instrument and provide as-needed assistance. In 2011, one researcher will return to Summit in mid-June to conduct minor maintenance on the seismometer. Summit staff will assist the researcher as needed with excavation of the bunker and maintenance activities. Year-round science technical staff will re-level the instrument and provide as-needed assistance. In 2012, two researchers will return to Summit Station in July to conduct minor maintenance on the seismometer. In 2013, two researchers will return to Summit Station in July with the following objectives: (1) relocate the seismometer to a new trench, and (2) replace the cable between the TAWO and the new seismometer trench. Summit Station staff will assist the researchers as needed with excavation of the bunker and maintenance activities. Year-round, science technical staff will re-level the instrument and provide as-needed assistance. In 2014, no researchers will deploy to Summit Station. Instead, station staff will assist with excavation of the bunker and maintenance activities as needed. Year-round, science technical staff will re-level the instrument and provide as-needed assistance. In 2015, two researchers will deploy to Summit Station in June to perform maintenance on the seismometer system, including relocating it to a new vault, raising all cables above the snow surface and checking out all hardware. Year-round, science technical staff will re-level the instrument, maintain data and power cables above the snow surface and provide as-needed assistance. No researchers will deploy in 2016. Instead, station technical staff replaced a broken seiscompbox. The replacement box is expected in fall 2016; when functioning, it will allow remote mass centering. In 2017, two researchers will visit Summit in May to perform maintenance on the seismometer system, including relocating it to a new vault, raising all cables above the snow surface, and checking out all hardware. The project team plans to install a post hole sensor for a 1-2 year comparison with the current seismic system to investigate potential replacement of the system in future years.

CPS will provide ANG travel and cargo support to/from Summit Station, Summit Station user days, a snow auger/corer with required tools, access to infrastructure, and year around science technician support for re-leveling the instrument, maintaining data and power cables above the snow surface, and general maintenance/troubleshooting as-needed). The PI will pay NSF directly for costs associated with this support. All other logistics will be provided by the PI.

This site is administered by the Science Coordination Office for Summit Station and the Greenland Traverse (University of New Hampshire, University of California - Merced, and Dartmouth). This material is based on work supported by the National Science Foundation under awards OPP-1637006 to the University of New Hampshire, OPP-1637209 to the University of California - Merced, and OPP-1637003 to Dartmouth College. Any opinions, findings, conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.